Zephyr1
Elite member
Lookin good mate! Except, both those links go to the Mig video ...
Well that is embarrassing...It's fixed now lol
Well that is embarrassing...It's fixed now lol
Zephyr1
Elite member
So the all up weight was 770g with a 2650 4S. The EDF I used weighed 120g. But the wing loading is relatively low as is. So it could work.
jpot1
Elite member
Thanks! F pack may be too little but I gave a 2200kv Turnigy that puts out 850 g of thrust. It weighs 50g and my 3s battery would save me as well so I think I’ll be good!
Zephyr1
Elite member
Nice! I don’t think weight is the issue, you might have to modify the elevators though, that would be the big thing I’d be worried about. Will you be taking my advice and including ailerons?
Zephyr1
Elite member
Shifting them forward sounds like a good idea. I think it needs ailerons, the elevons weren’t enough maneuverability for me lol.
I spliced it together near the the nose, thinking more weight in the nose was preferable.
Zephyr1
Elite member
Not yet. I only got one successful flight out of it so I'm going back and redesigning it now. It'll be up soon though.
Zephyr1
Elite member
Yeppers!
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Zephry thanks for this great design. I made a few changes from your plans. Re designed the turtle deck to house all of the electronics and added a vented battery tray in the cockpit to hold the battery above the internal ducting using BBQ skewers and a rubber band - battery gets cooling from the duct without being in the duct. All wiring is taped flush with the inside duct to reduce drag. Resized the nose opening slightly and installed a Freewing Mig-21 shock cone to improve the inlet flow. By doing all of that the AUW increased to 31oz but I was able to get the jet flying on an FMS 11 blade 50mm 4S fan unit. Because I fly at a small field I modified the wing reducing aileron span by 10% and adding bottom hinged plan flaps. When deployed the nose pitches up, so to improve pitch authority they are mixed to elevator - 15 degrees at full up stick. Loops, rolls, split-S and Immelmanns are all easily do-able and full throttle low passes are a blast. Launches at 25 degrees flap require a light toss and landings at 40 degrees flap are unbelievably slow - your design has amazing directional stability at low speeds with flaps!!
Awesome design. Cheers, Mate!
Awesome design. Cheers, Mate!
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Zephyr1
Elite member
That is so awesome! Any chance you have any more pics? Especially of ones flying? I'd love to see one of the flaps deployed. It's happened to me a few times, where someone takes my plans and just knocks it out of the park so much better than I have, and that's definitely you right now. Amazing job man
Zephyr, here’s a few shots of the flaps and battery tray/intake. The flaps are simple plain units hinged opposite the ailerons and with the control horns reversed to increase throw. With a 50mm fan installed the intake area minus the intake spike area and minus the profile frontal area of the wing is still more than the total area of the fan so in theory it breathes well. I tested that today by cutting a small cheater hole ahead of the fan.......best I can tell there was no performance gain so I think the fan was already breathing well.
I think the wing could be modified with a carbon rod embedded in the lower surface and the upper surface removed where it protrudes through the walls of the duct (maybe allow slight protrusion for strength then cover with canoe fairings to reduce turbulence in the duct). I think by doing that and adding some kind of “disguised” cheater hole you could feed a 70mm fan without losing any meaningful efficiency in the duct work.
Trying to talk my better half into videoing a flight...........Your plans turned out a seriously cool park jet!
I think the wing could be modified with a carbon rod embedded in the lower surface and the upper surface removed where it protrudes through the walls of the duct (maybe allow slight protrusion for strength then cover with canoe fairings to reduce turbulence in the duct). I think by doing that and adding some kind of “disguised” cheater hole you could feed a 70mm fan without losing any meaningful efficiency in the duct work.
Trying to talk my better half into videoing a flight...........Your plans turned out a seriously cool park jet!
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Zephyr1
Elite member
haha I won't hold the landing against you, it looks exceptional. I love that the nose cone is functional, and the flaps are such a fantastic touch. Where did you get the canopy for it? I did look at it some more and realized you built it with my older plans. I'm going to upload the newer ones, I'm not sure if you'd be as interested but I added a nozzle to the newer version that would make your's look that much better.
Well done my man
Well done my man
Zephyr,
I would definitely be interested in building the new version!! The canopy is a Freewing replacement part - got it for $4.99 and it looks better than my original soda bottle canopy. I'm headed out to HNL tomorrow but will be back Monday afternoon. Got a Masters Series Spitfire on the bench right now and a Ben Harber A-4 awaiting paint.............. but I'd like to build another Mig. I've got a few ideas for modifying the internals a bit more and it'd be a great excuse to do some testing with a bigger fan. Couple of questions:
1) What did your AUW end up being with the 70mm unit and did you bench test the thrust output? I'm only getting around 24oz static thrust on my 50mm fan. Want to get a bench mark for how much duct design and nozzle affect the thrust output of a 64/70mm unit. I know my current set up is maxed out without a cheater hole on 50mm because adding one produced no additional thrust output.
2) What is the heaviest you've flown it? How was the hand launch?
3) Did you test any other wing profiles or experiment with reducing the percentage of span that is under-cambered to get more speed? With the main wing planform being pure Delta it shouldn't have any tip stall tendencies even without under cambered tips and I think you could reduce drag significantly without increasing weight by much by making the wing flat bottomed? I built a "stick figure" swap-able-wing test bed for my Mig 15 and actually used your Mig 17 wing on it along with a flat plate airfoil, a KFm3 and KFm4. Your wing had by far the kindest stall characteristics and looked the best close up, but came in neck and neck with the KFm3 for speed. I opted for the KFm4 because of the shear speed difference on 50mm and the minimal duct restriction with the steps removed - My Mig 15 is seriously slippery although the wing isn't pretty she's a bullet on a 3S 50mm FMS unit.......Faster than the Mig21 on a 4S 50mm by a lot.
4) Will you be attaching your latest version to the first post in this thread?
Thanks for making these plans available Zephyr.
Cheers Mate!
I would definitely be interested in building the new version!! The canopy is a Freewing replacement part - got it for $4.99 and it looks better than my original soda bottle canopy
. I'm headed out to HNL tomorrow but will be back Monday afternoon. Got a Masters Series Spitfire on the bench right now and a Ben Harber A-4 awaiting paint.............. but I'd like to build another Mig. I've got a few ideas for modifying the internals a bit more and it'd be a great excuse to do some testing with a bigger fan. Couple of questions:1) What did your AUW end up being with the 70mm unit and did you bench test the thrust output? I'm only getting around 24oz static thrust on my 50mm fan. Want to get a bench mark for how much duct design and nozzle affect the thrust output of a 64/70mm unit. I know my current set up is maxed out without a cheater hole on 50mm because adding one produced no additional thrust output.
2) What is the heaviest you've flown it? How was the hand launch?
3) Did you test any other wing profiles or experiment with reducing the percentage of span that is under-cambered to get more speed? With the main wing planform being pure Delta it shouldn't have any tip stall tendencies even without under cambered tips and I think you could reduce drag significantly without increasing weight by much by making the wing flat bottomed? I built a "stick figure" swap-able-wing test bed for my Mig 15 and actually used your Mig 17 wing on it along with a flat plate airfoil, a KFm3 and KFm4. Your wing had by far the kindest stall characteristics and looked the best close up, but came in neck and neck with the KFm3 for speed. I opted for the KFm4 because of the shear speed difference on 50mm and the minimal duct restriction with the steps removed - My Mig 15 is seriously slippery although the wing isn't pretty she's a bullet on a 3S 50mm FMS unit.......Faster than the Mig21 on a 4S 50mm by a lot.
4) Will you be attaching your latest version to the first post in this thread?
Thanks for making these plans available Zephyr.
Cheers Mate!
Zephyr1
Elite member
Zephyr,
I would definitely be interested in building the new version!! The canopy is a Freewing replacement part - got it for $4.99 and it looks better than my original soda bottle canopy
1) What did your AUW end up being with the 70mm unit and did you bench test the thrust output? I'm only getting around 24oz static thrust on my 50mm fan. Want to get a bench mark for how much duct design and nozzle affect the thrust output of a 64/70mm unit. I know my current set up is maxed out without a cheater hole on 50mm because adding one produced no additional thrust output.
2) What is the heaviest you've flown it? How was the hand launch?
3) Did you test any other wing profiles or experiment with reducing the percentage of span that is under-cambered to get more speed? With the main wing planform being pure Delta it shouldn't have any tip stall tendencies even without under cambered tips and I think you could reduce drag significantly without increasing weight by much by making the wing flat bottomed? I built a "stick figure" swap-able-wing test bed for my Mig 15 and actually used your Mig 17 wing on it along with a flat plate airfoil, a KFm3 and KFm4. Your wing had by far the kindest stall characteristics and looked the best close up, but came in neck and neck with the KFm3 for speed. I opted for the KFm4 because of the shear speed difference on 50mm and the minimal duct restriction with the steps removed - My Mig 15 is seriously slippery although the wing isn't pretty she's a bullet on a 3S 50mm FMS unit.......Faster than the Mig21 on a 4S 50mm by a lot.
4) Will you be attaching your latest version to the first post in this thread?
Thanks for making these plans available Zephyr.
Cheers Mate!
That's awesome! I'll look into the canopy for myself.
3. I will get back to you on questions 1 & 2. But as for 3 and 4. Yes, I changed the wing to be completely flat bottomed. I also removed the paper from the top of the wing to make it look better, and it handles beautifully, with a little more speed. That's awesome that someone is getting some use out of the MiG-17 plans, I love that little plane.
4. Yes, I'll be replacing the current plans at the top of the thread.
Zephyr,
Been slow on thee V2 build. Had to finish the Master Series Spitfire and working on a twin 50mm ME262 as well. Here’s what I’ve got so far:
1)Modified the fuselage to increase circumference by 40mm to allow for the nose spike assembly.
2)re-drew the nozzle, for some reason my printing software must have flattened the image because it didn’t form a cone shape when rolled.
3) added pockets on the vertical stab to insert BBQ skewers into for added strength. (Probably overkill but I did it on the 50mm one too - and the fold-over pockets make it look better than my first attempt). Also removed the 3rd tab at the trailing edge and sloped the lower surface to match the nozzle.
4)added chopsticks to strengthen the lower wing skin and redesigned the lower wing to hold the 64mm fan just aft of the CG. This should allow me to move the battery back almost directly over the CG and make the jet more responsive in pitch. Marked up the lower surface for a pair of split flaps (not plain like I did on V1). V1 was such a floaty jet to land With flaps that I’m thinking a shorter chord split flap extended to 50-60 degrees should create far more drag than lift and make her settle in for landings without as much float.
Anyhoo - here it is........
Been slow on thee V2 build. Had to finish the Master Series Spitfire and working on a twin 50mm ME262 as well. Here’s what I’ve got so far:
1)Modified the fuselage to increase circumference by 40mm to allow for the nose spike assembly.
2)re-drew the nozzle, for some reason my printing software must have flattened the image because it didn’t form a cone shape when rolled.
3) added pockets on the vertical stab to insert BBQ skewers into for added strength. (Probably overkill but I did it on the 50mm one too - and the fold-over pockets make it look better than my first attempt). Also removed the 3rd tab at the trailing edge and sloped the lower surface to match the nozzle.
4)added chopsticks to strengthen the lower wing skin and redesigned the lower wing to hold the 64mm fan just aft of the CG. This should allow me to move the battery back almost directly over the CG and make the jet more responsive in pitch. Marked up the lower surface for a pair of split flaps (not plain like I did on V1). V1 was such a floaty jet to land With flaps that I’m thinking a shorter chord split flap extended to 50-60 degrees should create far more drag than lift and make her settle in for landings without as much float.
Anyhoo - here it is........
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